Closing a flue


  #1  
Old 10-08-11, 12:23 PM
J
Member
Thread Starter
Join Date: Dec 2010
Location: USA
Posts: 40
Upvotes: 0
Received 0 Upvotes on 0 Posts
Closing a flue

I have a chimney with 2 flues for 2 fireplaces that we never use. In the winter these just leak cold air. I've tries blocking the top of the fireplaces where the doors to the flue are with plastic, covering the fronts with plastic (which worked pretty well last winter).

This year I want to try getting a single roofing shingle, cutting it into 2 pieces a little larger than the flue opening on top of the chimney outside (to make a seal) and then putting 2 square concrete patios bricks on top of the shingle cutouts.

Any thoughts?
 
  #2  
Old 10-08-11, 05:08 PM
M
Forum Topic Moderator
Join Date: Mar 2005
Location: USA - N.E.Tn
Posts: 45,619
Received 824 Upvotes on 722 Posts
I don't know about the shingle, it seems to me that would be something that could accidentally fall into the flue although I see quite a few that use a masonry block over the top. I'd use a bead of caulk for the seal. Ideally you use a metal cap that would come down the sides.
 
  #3  
Old 10-08-11, 05:19 PM
J
Member
Thread Starter
Join Date: Dec 2010
Location: USA
Posts: 40
Upvotes: 0
Received 0 Upvotes on 0 Posts
Thanks. Good to know that others are doing the same thing.
 
  #4  
Old 10-08-11, 07:32 PM
BridgeMan45's Avatar
Member
Join Date: Oct 2011
Location: USA
Posts: 2,838
Upvotes: 0
Received 2 Upvotes on 2 Posts
Perhaps a silly question, but you do have both dampers (above the smoke chambers) closed, yes? A few years ago I fabricated a snug-fitting flue cover with a handle on it, out of scrap steel. Easy enough to remove when necessary, but heavy enough that it never blew around in a stiff wind.
 
  #5  
Old 10-08-11, 08:10 PM
J
Member
Thread Starter
Join Date: Dec 2010
Location: USA
Posts: 40
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yup, dampers are closed. One year I even made a wood frame to fit snug at the top of the fireplaces right under the damper with plastic and insulation and more wood and it still leaked - but that was in the dead of the winter and I wasn't going up to the chimney. Sounds like I need your flue cover. If the concrete block works, I'll make something more permanent next year.
 
  #6  
Old 10-18-11, 08:05 PM
E
Member
Join Date: Feb 2010
Location: U.S.A.
Posts: 364
Upvotes: 0
Received 0 Upvotes on 0 Posts
I don't remember the name, but I saw it on one of the many home improvement shows I watch. It looked like a square inner tube, you stuck in the flue, and pumped it up to seal off the flue.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: